Lecture 1 Flashcards
(18 cards)
definition nutrition
- The science of the study of food, nutrients and other substances within food:
- Their action, interaction, and balance in relation to health and disease, growth, reproduction
- And the processes by which the body ingests, digest, absorbs, transports, utilizes, stores and excretes nutrients
- Interaction with the genes, genome and epigenetics to regulate metabolism
The study of the environment and of human behaviour as relevant
roles of nutrients
- Raw materials:
- Maintenance and repair of tissues
- Growth
- Regulate vital processes in the body
Source of energy (only for macronutrients)
8 severe deficiency diseases
- Protein energy malnutrition
- Anemia (iron)
- Xerophtalmia (vitA)
- Goiter (iodine)
** these 4 deficiency affect millions of people - Beriberi (thiamin, vitB1)
- Pellagra (niacin)
- Scurvy (vitC)
Rickets (vitD)
7 points of nutrition now
- Chronic disease prevention:
- Cancer, cardiovascular disease, diabetes
2. Obesity
3. Gut microbiota
4. Disordered eating
5. Childhood issues
6. Genotype-specific effects
7. GMOs
8. Food production/distribution
9. Eating local
Natural health products
- Cancer, cardiovascular disease, diabetes
5 steps scientific method
- Observation and question
- Identify a problem to be solved or ask a specific question to answered
2. Hypothesis and prediction
3. Experiment
4. Results and interpretations
5. Hypothesis supported= theory
Or
Hypothesis not supported = new observations and questions
- Identify a problem to be solved or ask a specific question to answered
6 examples of research designs
EPIDEMIOLOGICAL STUDIES: research the incidence, distribution, and control disease in a population: 1. Cross-sectional studies 2. Case-control studies 3. Cohort studies EXPERIMENTAL STUDIES: test cause-and-effect relationships between variables 4. Laboratory-based animal studies 5. Laboratory-based in vitro studies Human intervention (or clinical) trials
cornerstones of nutrition research
- Randomized placebo-controlled double-blinded clinical trials
- Sample size
- Representative sample
- Replication
Ethics primary over-arching principle
from research to population health
- Nutrition research studies
- Published in peer-reviewed journals
2. Expert scientific evidence-based review - Dietary reference intake reports
3. Public health message - Health canada
Depth health and human services, US dept of agriculture (USDA)
- Published in peer-reviewed journals
characteristics essential nutrients + ex
- Performs an identifiable biological function
- Abnormality results if omitted from diet, which is corrected when added back to diet
- Required in the diet because the body cant make it all, or cant make it fast enough to satisfy the need for it
Ex: cholesterol is a really critical nutrient for cell membrane, its an hormone.. But if we take it out of the diet nothing happens because we can do it a lot = NONESSENTIAL
Ex: Vitamin C is essential in the diet!!
Ex: ascorbic acid is essential to human but if you take it out from the diet of the dog, nothing happens because most mammals can do it abundantly
Ex: arginine, premature babies cant make a lot so = essential! But not for adults
estimated average requirement (EAR)
Def EAR: the average daily amount of a nutrient that will maintain a specific biochemical or physiological function in half the healthy people of a given age and gender group
- To achieve some measurable biochemical or functional outcome - To avoid deficiency (not overcome) - To maintain long-term good health (not attain) * * determined by experimentation in a healthy population group
setting recommendations
A committee examines nutrition research data and uses its best judgment to set a safe level of dietary intake that will meet the requirement of essentially all healthy peopple without undue risk of toxicity
- Evidenced-based recommendations
If you dont know, say so!!!
recommended intake of nutrients
- WHO/FAO/UNU - World health organization
- Canada/USA harmonize:
1. Dietary reference intake (DRI)
2. Systematic evaluation of current knowledge of nutrient data
3. Committees of sceintists expert in their fields
Upcoming harmonized with WHO
- Canada/USA harmonize:
mandate of DRIs committees
- Develop DRIs:
- Evaluate nutrient regts including new nutrients
- Intake of nutrients, supplements and non-nutrients, bioavailability, absorption, metabolism, nutrient interactions
- Safe range of intakes, different levels of info
2. Roles in preventing or delaying onset of chronic disease or developmental abnormalities
3. Make recommendations for food labelling, fortification
Identify research needs
EAR, RDA, AI, UL
EAR: estimated average requirement
- Meets requirements of half of the indivudals in a group
RDA: recommended dietary allowance
- Mean requirement plus allowance to meet the needs of almost all healthy people in a group
UL: tolerable upper intake level
- Max intake without adverse health effects for group
- No benefit if intake is higher than RDA, AI
AI: adequate intake
- Not enough info to establish requirement
- Mean intake which sustains health in a group
AMDR (acceptable macronutrient distribution range)
Fat: 20-35% of energy intake
CHO: 45-65%
Protein: 10-35%
recommendations of DRI
- Apply to healthy people
- Target most people
- Intake met through a variety of foods
- Usual dairy intakes of nutrients
EER VS EAR, EAR vs RDA
what do we use for group (EAR or RDA)
EAR
- Plan and procure food supplies for schools etc
- To establish guidelines for public assistance programs
- To develop new food products by industry
To design nutrition education programs
what do we use for individuals (EAR or RDA)
- Intake less than RDA does not mean deficiency but only greater relative risk
- No benefit from intakes higher than recommended
- Intake is assessd over a period of time (i.e. average daily intakes not intakes every day)
